1. Technical Field
The disclosure relates to a cross section processing method and a cross section processing apparatus for processing an observation surface of a sample which is observed by a microscope, by using a focused ion beam.
2. Description of the Related Art
For example, when observing and analyzing a sample such as a semiconductor device by a scanning electron microscope (SEM), a transmission electron microscope (TEM), an energy dispersive X-ray spectrometry (EDS), electron backscatter diffraction (EBSD), or the like, it is necessary to form a flat observation surface of the sample. In a case where an observation surface is not flat, it becomes difficult to obtain an accurate image of an observation surface (a cross section) or perform accurate component analysis.
In the past, in the formation of such an observation surface of the sample, a flat observation surface has been formed by polishing the sample or by the cleavage of the sample. However, in a case of polishing the sample, there is a concern that the sample may be contaminated by an abrasive or the like. Further, in a case of cleaving the sample, it is limited to a case where the sample is a crystalline substance.
For this reason, in recent years, as one of techniques of forming a flat observation surface of the sample, cross section formation processing (etching) by a focused ion beam (FIB) has been used (for example, JP-A-2008-270073). A method of forming an observation surface of the sample by using such a focused ion beam has the advantage of being able to accurately form a fine observation surface at an optional position of the sample, which is not present in other formation methods.